Determination of the Space-Time Extension of Centrally Produced Hadronic Matter Using the Intensity Interferometer Technique in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>pp</mml:mi></mml:math>Interactions at 28.5 GeV/<i>c</i>

Abstract

We have measured in the central region, the ratio of negative pion pairs to that of negative-positive pion pairs as a function of the Kopylov variables. A correlation was observed. From the shape of the correlation function we determined the radius $r$ and life-time $\ensuremath{\tau}$ of the centrally produced hadronic matter parallel and perpendicular to the collision axis to be ${r}_{\ensuremath{\parallel}}={0.73}_{\ensuremath{-}0.11}^{+0.10}$ fm, ${r}_{\ensuremath{\perp}}={1.65}_{\ensuremath{-}0.99}^{+3.56}$ fm, and ${\ensuremath{\tau}}_{\ensuremath{\parallel}}=({1.97}_{\ensuremath{-}0.56}^{+0.57})\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}24}$ sec.